How To Check Coolant Level?

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how to check coolant level

Car engines are temperature sensitive, and they need to be kept in an operating temperature range of approximately 212°F (100°C) to 649°F (340°C). When the car is started cold, it can be difficult to get it up to this temperature without driving.

A lot of people don’t realize that the coolant needs to circulate through the engine and be heated by it before the car will start to warm up. This is why maintaining an adequate level of coolant in your car’s radiator is so important, as the system will never reach full operating temperature if there is air trapped inside.

This article will cover all there is to know about checking the coolant level in your coolant reservoir.

What is the Engine Coolant?

Engine coolant or antifreeze is a special kind of liquid used in vehicles to make the engines run smoothly. The main reason for this coolant or antifreeze is to control the engine’s temperature, and it performs its function by getting rid of extra heat from the engine. The boiling point of antifreeze is 223 Fahrenheit.

In return, it keeps your car’s engine from overheating. It is mostly made with a mixture of water and ethylene glycol or propylene glycol, with an additive chemical to stop it from freezing at low temperatures.

There are two different types of coolant- one which contains propylene glycol and another one that contains ethylene glycol because the one which contains ethylene glycol is toxic and can be fatal for animals. So if you ever happen to spill it on the ground, make sure that you clean it properly and do not let any animal or person come in contact with it.

The coolants can come in different colors like orange, red, green, purple, etc. The color of the coolant depends on the manufacturer. Most propylene glycol-based coolants are colored pink or light red, and ethylene glycol ones are colored bright green or yellow.

Why is it Important to Maintain the Coolant Level?

If you continue to drive with a low coolant level, the following things can happen to you:

Engine damage

Damaged pistons and other engine parts may result from continued driving. Remember, driving allows the engine to keep on spinning. The engine is designed for this, but only up to a certain temperature. Engine overheating can cause serious issues for your car.

Leaking Coolant

If there is not adequate coolant in the system, it can boil, spin out of control and cause coolant leaks. The remedy here depends on where the system is leaking.

No heat

A low level may also mean you don’t have any heat coming out of your heater during cold weather. This is because the level needs to be high enough to move the coolant back and forth from the engine. If it’s not, you may have a blown heater core.

Increased emissions

With increased engine temperatures, your car may emit higher levels of pollutants into the air.

Oil contamination

Contamination can occur because of oil seepage into the cooling jacket.

Higher fuel consumption

Increased engine temperatures result in increased fuel consumption.

System leaks

Continued driving can cause leaking seals that may lead to more expensive repairs. Also, coolant contains lubricants and corrosion inhibitors, which protect against rust and

Carbon Deposit Buildup

Unburned gasoline can cause carbon deposits to build up in your engine. Clogged fuel injectors can cause reduced power or poor performance, while carbon deposits on combustion chamber surfaces can reduce the engine’s compression.

Carbon Deposit Build on intake valves and in the combustion chamber, reducing fuel economy by as much as 3%. Carbon deposits can also restrict exhaust flow, resulting in reduced power, poor performance, and increased emissions.

Starting Problems

Your car may not start the next time you turn the ignition key. This is because once a car’s engine has overheated, the reduced coolant level has allowed the radiator to dry out.

Because there is no more water in the coolant system, there is nothing for the electric motor that operates the water pump. The car will not start until you add water back into your cooling system and bleed it to get fresh coolant to the radiator.

How To Check Your Coolant Level?

This is how you can check if there is enough coolant in your car’s engine:

1. Locate the Coolant Reservoir

First of all, you need to locate the coolant tank. Locating the coolant reservoir is easy. If you look below or to the side of your car’s engine, you’ll see a plastic tank that usually has an opening on the top and overflow openings along the sides. This is what houses your radiator fluid, which should be at least half full for your engine to run properly.

2. Remove Coolant Reservoir Cap

To determine the optimal level, you must first remove the cap from the reservoir. Some coolant reservoirs have a rubber or plastic piece attached to the cap, which you should pull off before removing it. This is especially common in newer cars.

3. Check Your Coolant Level With a Dipstick

After removing this piece, open up your coolant reservoir and check its contents against the dipstick that should be inserted into the opening. If your fluid level is low, you can add coolant by pouring it directly into the reservoir.

4. No Dipstick Found?

If you can’t find any dipsticks to check your coolant levels with, chances are there isn’t one in your vehicle. This means that you’ll need to open up the radiator cap of the radiator itself, located on top of the engine. Make sure that you turn off your car and wait for it to cool down before attempting this.

5. Add New Coolant in Overflow Reservoir

Once open, a good amount of fluid should be visible inside the radiator. If your coolant levels are low here as well, you’ll need to add more fluid here as well in order to get the right amount necessary for your engine.

6. Don’t Overfill

Don’t overfill, though! Once you’re satisfied with your coolant levels, give it a quick stir with a long-handled tool and close up the cap on the radiator. This will help prevent any antifreeze from boiling or evaporating as you drive your car.

7. Check For a Leak

If you check your car’s coolant levels and find that they’re low, you may need to bring it to a mechanic. Low fluid levels can be caused by leaks in the cooling system, an overheating engine, or problems with your heater. If any of these issues are the source of your problem, you should seek professional help as soon as possible.

8. Remove Air Bubbles

If there is any air trapped in your car’s cooling system, this may cause overheating the engine. In order to remove this air from the system, keep the ignition key in the ON position for at least 10 minutes without starting your engine. After 10 minutes, switch off the ignition and wait for about 5 minutes to release any remaining pressure through the filler cap.

9. Recheck Coolant Level

Now recheck the coolant level in your cooling system for any possible leakage and if you find it less than the maximum level, add an equal amount of distilled water to reach the maximum level mark. After checking the coolant level, replace the radiator cap very slowly and carefully.

10. Test Drive

Now start your engine and keep a safe distance from any possible obstruction or person standing in front. If there is even a slight overheating, it may cause a popping sound from under your car’s hood, i.e., an overheating pressure relief valve.

Safety Guidelines To Check Coolant Levels

You must follow these guidelines before adding or checking the hot coolant level:

  1. Before checking your car’s radiator coolant level, ensure that the vehicle is parked on a level surface.
  2. Also, remember that if the air temperature is hot or in the case of direct sunlight, then wait for some time until the engine cools down.
  3. Even though this process is time-consuming, it ensures the safety of yourself and your loved ones.
  4. You are advised to wear gloves while checking the coolant level in your car’s radiator. If the car engine is hot, the burning oil may cause skin irritation or burns.

Now check whether any of the following conditions apply to your car:

  1. If the vehicle has a plastic overflow container.
  2. If the radiator cap has a warning label, “Do Not Top Up.”
  3. If you cannot see your coolant reservoir or an overflow bottle in the engine compartment.

If any of the above-mentioned conditions apply to your car, never try to top up your water yourself without consulting a service center. After all, it is in your best interest to ensure the car’s proper functionality and your own safety.


The coolant in your car is responsible for maintaining the optimal engine operating temperature. Your car’s internal cooling systems are essential for optimum engine performance, fuel economy, and emission control. A fluid leak or lack of coolant is a concern, as the engine could overheat and be severely damaged.

A lack of coolant may not allow the engine to operate at its optimum temperature. If the engine overheats, then various components in your car can be severely damaged, including the electrical system, radiator hoses, head gasket, and engine block. In very serious cases, a lack of coolant can cause the engine to seize completely due to bearing failure and other costly damage.

Check your coolant level immediately when you receive notice that your car requires a coolant check. When you need a new coolant, consider getting a proper coolant replacement that will keep your vehicle running smoothly for years to come.

Frequently Asked Questions

What to do if you are running low on coolant?

If you run low on coolant often, consider having the cooling system pressure tested to see if it’s leaking. Make sure that all hoses and connections are secure and properly tightened before having your vehicle inspected.

How do I top up my car’s coolant level?

Topping off your car’s cooling system is both an easy and affordable way to take care of your vehicle. Remember: the correct amount of coolant depends on several variables, such as size and location, so check your owner’s manual for exact specifications.

Your car’s reservoir is typically located near the front of the engine compartment and usually has a cap that is easy to remove. Simply add a 50/50 mixture of water and coolant at the recommended level for a quick refill. Take care not to overfill your cooling system as this can be dangerous.

Can I reuse my old coolant?

It’s generally recommended that you use a mixture of 50 percent coolant and 50 percent water in your coolant system. Unless the container is dated, there’s no way to tell how long the old coolant has been stored, so it should be disposed of responsibly.

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